Schismatoglottis imbakensis Kartini, S.Y.Wong &

Wong, Sin Yeng & Joling, Jyloerica, 2021, Checklist of aroids (Alismatales, Araceae) from Sabah (Malaysian Borneo), Check List 17 (3), pp. 931-974 : 964

Schismatoglottis imbakensis Kartini, S.Y.Wong &

P.C.Boyce Literature cited. MALAYSIA – Sandakan • Telupid,

Imbak Canyon Conservation Area, Sungai Kangkawat; 05°5′05′′N, 117°03′20′′E; ca. 260 m elev.; 1 Oct 2018; Kartini et al. 2705 (holo, BORH + spirit).

Identification. Schismatoglottis imbakensis is distinguished from S. retinervia Engl. , the only other species of the Patentinervia clade occurring in Sabah, by the plant glabrous (vs. petioles and abaxial midribs puberulous), by the naked sterile interstice of the spadix equalling the pistillate floret zone (vs. naked sterile in- terstice hardly developed), by the deep green pistils with the stigma about half the width of the ovary (vs. pistils dirty pale green with the stigma almost equalling the ovary width), by the staminate florets somewhat laxly ar- ranged and the stamens readily discernible (vs. staminate florets very densely packed and individual stamens scarcely distinguishable). Schismatoglottis imbakensis is distinguished from S. pichinensis P.C.Boyce and S. puncakborneensis P.C.Boyce , the other two Patentinervia clade species with a long naked sterile interstice, by large rhomboidal cream interpistillar staminodes (vs. interpistillar staminodes lorate or if rhomboidal then small and white), the large, laxly arranged stamens (vs. small and congensted), and sharply pointed (vs. blunt) spadix appendix ( Kartini et al. 2020).

Distribution and ecology. Endemic to Sabah. Known only from the type locality on the Sungai Kangkawat, Imbak Canyon Conservation Area. Primary lowland mixed dipterocarp forest on Cretaceous Harzburgite and Serpentinite outcrops, occurring on steep, muddy riverbanks above the flood zone, ca. 270 m elev.